The Wide-Field Infrared Survey Telescope (WFIRST) will image large regions of the sky in near-infrared light to answer fundamental questions about dark energy and the structure and evolution of the universe. It will also greatly expand our knowledge of planetary systems around other stars, and revolutionize many other astrophysical topics. Slated to launch in the mid-2020s, the observatory will operate at a gravitational balance point known as Earth-sun L2, which is located about 930,000 miles from Earth in a direction directly opposite the sun.